Oleksandr Prokopovych Markevych (), in English more often Aleksandr Prokofyevich Markevich () (19 March 1905 – 23 April 1999) was a Ukrainian zoologist, and a prolific helminthologist and copepodologist. He was professor and an Academician of the National Academy of Sciences of Ukraine. Biography Markevych was born 19 March 1905 in the village of Ploske, Kyiv Governorate. His father Prokofiy Markevych served as a parish clerk in a rural church. His mother Maria Bordashevska came from a family of the impoverished nobility. During his studies at the Pedagogical Technical School (1921–1925) in Belaya Tserkov, he was engaged in research on ichthyology. He continued his studies at Kyiv University, where he worked in the laboratory of I. I. Schmalhausen and simultaneously at the biological station of the Ukrainian Soviet Socialist Republic Academy of Sciences, situated on the Dnieper River. His keen interest in fish parasites led him to work at the Ichthyological Institute of the Lenin All-Union Academy of Agricultural Sciences in Leningrad (now the Research Institute of the Lake and River Fish Industry), where he completed his post-graduate studies under the guidance of professor V. A. Dogiel. In the 1930s a team of scientists at the Laboratory of Fish Diseases, headed by Dogiel, laid the foundations of Soviet ichthyoparasitology. At this laboratory the young Markevich began to study the then little known and very complicated group Copepoda parasitica, with extraordinary diligence and perseverance. He studied the fauna of this group living in lakes Ladoga and Onega, in the Caspian and Azov seas and in a number of smaller water bodies. In 1935 he returned to Kyiv, where at first he headed the Invertebrate Morphology Department of the Zoological Institute, in the Ukrainian SSR Academy of Sciences, then in 1937 became head of the newly established Parasitological Department of that Institute. Scientific career and publications Markevich was one of the first Soviet parasitologists to begin a systematic study of fishpond culture. He was the first to publish that the dangerous fish parasite Chilodonella cyprini reproduces massively in the winter and not in the summer, as supposed earlier. His key papers described the new species of parasitic copepods Ergasilus briani Markevich, 1932 Paraergasilus rylovi Markevich, 1937 Ergasilus auritus Markewitsch, 1940 Ergasilus anchoratus Markewitsch, 1946 After returning to Kyiv in 1935 Markevich continued his ichthyoparasitological investigations. In 1951 he published an extensive monograph on the parasite fauna of freshwater fishes of the Ukrainian